Abstract: The probability of sub-synchronous oscillation (SSO) has increased significantly with the growing penetration of wind power generation in power system. SSO has been reported that it brought major challenges to the safe and stable operation of power system equipment. How to accurately identify SSO parameters is extremely important to suppress SSO. To utilize synchronized measurement data and improve the calculation accuracy and reduce the influence of spectrum leakage and fence effect on identification, this paper proposed an innovative identification method of SSO key parameters using complex-domain synchrophasor data. First, the expression of windowed phasor with SSO signal in complex number domain was obtained through spectrum analysis, and the characteristics of system fundamental frequency component and SSO component were derived in frequency domain. Then based on damped Rife-Vincent window and three-point interpolation method the frequency, damping factor, amplitude and phase parameters of SSO were calculated in the complex domain. The effectiveness of the proposed method was verified by identifying simulated signals under different conditions. The simulation results show that, compared with the traditional method, the proposed method can better suppress the spectrum leakage and fence effect, and obtain higher calculation accuracy and robustness.